Method for purifying and refining refined glufosinate ammonium salt

Abstract

The invention relates to the technical field of pesticide chemical industry, in particular to a method for purifying and refining refined glufosinate ammonium salt, which comprises the following steps: S1, enabling refined glufosinate ammonium salt mother liquor to pass through a nanofiltration membrane to obtain a refined glufosinate ammonium salt solution after sodium is removed; s2, after the sodium-removed refined glufosinate ammonium salt solution enters an electrodialysis system, an ammonium chloride salt solution and a refined glufosinate solution are obtained; s3, evaporating and concentrating the ammonium chloride salt solution to obtain an inorganic salt product; s4, carrying out evaporation and concentration treatment on the refined glufosinate-ammonium solution to obtain a refined glufosinate-ammonium product; the electrodialysis system comprises a cation exchange membrane and an anion exchange membrane; and the anion exchange membrane is a polyarylether sulfone anion exchange membrane. The separated glufosinate-ammonium is high in purity and low in loss rate, the yield of refined glufosinate-ammonium in the whole process reaches 98% or above, and the purity of refined glufosinate-ammonium reaches 99% or above.

Description

Technical Field

[0001] This invention relates to the field of pesticide chemical technology, specifically to a method for purifying and refining glufosinate-phosphonium salt. Background Technology

[0002] Glufosinate is a highly effective, low-toxicity, non-selective phosphonic acid herbicide that is gradually replacing glyphosate and paraquat due to its environmentally friendly properties. The production of glufosinate typically yields a mixture of ammonium and sodium salts, with large amounts of sodium chloride and ammonium chloride as byproducts, necessitating purification. Existing purification processes are divided into chemical and physical methods. Chemical methods require the use of hazardous chemicals and are complex, resulting in low yields, high costs, and difficulties in continuous production. Physical methods primarily utilize membrane separation technology, including nanofiltration and electrodialysis. While these methods enable continuous production and avoid the use of hazardous chemicals, they still have some limitations in ion selectivity.

[0003] Patent CN117105976A discloses a method for separating and purifying glufosinate and its byproducts. The method first involves introducing an ammoniacal solution containing glufosinate, ammonium chloride, and organic amine salts into an electrodialysis system for desalination and separation, completing the separation of ammonium chloride to obtain a finished product containing only glufosinate and a small amount of organic amine salts. The finished product crystallizes to obtain high-purity glufosinate. The mixed brine produced by the electrodialysis system is then subjected to nanofiltration to recover the permeated glufosinate and some organic amine salts, yielding dialysis brine almost free of glufosinate. The dialysis brine is then crystallized to obtain a high-content byproduct, ammonium chloride. However, it is difficult to obtain a high-purity glufosinate product through only the first step of nanofiltration.

[0004] Patent CN117003790A discloses a method for purifying and refining glufosinate-ammonium salt, comprising the following steps: mixing ammonium chloride solution and glufosinate-ammonium mixed salt reaction solution, followed by ion dialysis to obtain an inorganic salt mixed salt solution and a glufosinate-ammonium salt solution; the glufosinate-ammonium mixed salt reaction solution contains sodium chloride. This method solves the problem of difficult removal of sodium from glufosinate-ammonium mixed salts using membrane processes. Another method involves introducing ammonium chloride solution into the glufosinate-ammonium mixed salt reaction solution in a nanofiltration device and filtering, followed by ion dialysis to obtain an inorganic salt mixed salt solution and a glufosinate-ammonium salt solution, which is then used to prepare glufosinate-ammonium salt via coupled nanofiltration membrane or electrodialysis desalination. This solves the problem that glufosinate-ammonium salt cannot be directly prepared from glufosinate-ammonium salt containing sodium chloride through nanofiltration membrane or electrodialysis. However, this purification and refining method is costly.

[0005] Therefore, there is an urgent need in the market for a method of purifying and refining glufosinate with good purification effect and low cost. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of this invention is to obtain a method for purifying and refining glufosinate-phosphonium salt with excellent purification and refining effect and low cost.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a method for purifying and refining glufosinate-ammonium salt, comprising the following steps: S1. The mother liquor of glufosinate-ammonium salt is filtered and decolorized through a nanofiltration membrane to obtain a sodium-free glufosinate-ammonium salt solution. S2. The sodium-removed glufosinate solution obtained in step S1 is introduced into the desalination chamber of the electrodialysis system for desalination and concentration. Pure water is added to the concentrate chamber as the receiving liquid to obtain ammonium chloride solution and glufosinate solution. S3. The ammonium chloride solution obtained in step S2 is evaporated and concentrated to obtain an inorganic salt product; S4. The glufosinate solution obtained in step S2 is evaporated and concentrated to obtain glufosinate product. The electrodialysis system includes a cation exchange membrane and an anion exchange membrane; the anion exchange membrane is a polyarylether sulfone anion exchange membrane.

[0008] Preferably, the cation exchange membrane and the anion exchange membrane are arranged alternately.

[0009] This application involves first nanofiltration of the glufosinate mother liquor to obtain a sodium-removed glufosinate solution, which is then subjected to electrodialysis in an electrodialysis system containing both a cation exchange membrane and a polyarylene ether sulfone (PASsulfone) anion exchange membrane. This process yields an ammonium chloride solution and a glufosinate solution, which are then concentrated by evaporation to obtain the inorganic salt product and the glufosinate product. The aromatic ring structure and sulfone groups of the PASsulfone framework endow the ion exchange membrane with excellent mechanical and heat resistance properties. Its aromatic ether structure resists free radical attack, extending the service life of the ion exchange membrane. Compared to perfluorinated ion exchange membranes, PASsulfone is also more environmentally friendly.

[0010] In some embodiments, the nanofiltration membrane has a molecular weight cutoff range of 200-500 Da.

[0011] In some embodiments, the operating pressure of the electrodialysis system is 4-8 MPa; the pH of the freshwater chamber is 2-3.

[0012] In some embodiments, the method for preparing the polyarylene ether sulfone anion exchange membrane includes the following steps: A1. Add carvedilol to an aqueous ethanol solution, stir at 60-70℃ for 10-20 min, adjust the pH to 1-3, stir for 1-3 h, and dry to obtain the compound; A2. Add the compound obtained in step A1 and 4,4'-difluorodiphenyl sulfone to N-methylpyrrolidone, stir at room temperature for 10-20 min, add potassium carbonate and dimethyl sulfoxide, heat to 120-150℃ and react for 3-5 h, then heat to 160-180℃ and react for 3-5 h, cool to 70-90℃ to obtain the reaction solution; A3. Add bisphenol AF, 4,4'-difluorodiphenyl sulfone, potassium carbonate, dimethyl sulfoxide and N-methylpyrrolidone to the reaction solution obtained in step A2, heat to 130-150℃ and react for 3-5 hours, then heat to 160-180℃ and react for 3-5 hours to obtain the product. Add the product to deionized water to obtain the precipitate, wash and dry to obtain polyarylene ether sulfone. A4. Add the polyarylene sulfone obtained in step A3 to tetrachloromethane, stir to dissolve, cool to 0°C, add chloromethyl ethyl ether and tin tetrachloride, heat to 25-45°C and react for 2-3 days to obtain the reactant. Add the reactant to ethanol to obtain the precipitate, wash and dry to obtain chloromethylated polyarylene sulfone. A5. Add the chloromethylated polyarylene sulfone obtained in step A4 to tetrachloroethane and stir for 20-30 minutes. Then add tetramethylpropylenediamine and stir for 20-30 seconds. Finally, cast the mixture onto a flat glass surface, dry it, and peel it off to obtain the membrane material. A6. The membrane material obtained in step A5 is immersed in trimethylamine aqueous solution, sodium hydroxide aqueous solution and deionized aqueous solution for 24 hours each, and then dried to obtain polyarylether sulfone anion exchange membrane.

[0013] This application synthesizes a block-structured polyarylether sulfone by setting the order of addition of monomer raw materials. Compared with random copolymers, the block-structured ion exchange membrane has better conductivity and thus higher ion permeability, which is beneficial to improving the yield of glufosinate. Furthermore, this application can improve the ion exchange rate of polyarylether sulfone anion exchange membrane by introducing carvedilol segments onto the polyarylether sulfone chain. This may be because: (1) the carbazole group with large steric hindrance on the carvedilol segment can inhibit the free rotation of the polyarylether sulfone backbone, making the polymer form a looser stacking structure, thereby creating more nanoscale pores in the membrane and promoting ion conduction; (2) the increased incompatibility between the carbazole group and the flexible ether sulfone chain promotes the microphase separation of the quaternary ammonium group and the hydrophobic backbone, forming a continuous ion channel. The quaternary ammonium group near the carbazole group unit is forced to extend due to steric hindrance, exposing more active sites and improving the effective ion exchange capacity. On the other hand, carvedilol contains multiple amino groups that can be protonated under acidic or neutral conditions, serving as temporary binding sites for anions and promoting ion migration.

[0014] In some embodiments, the concentration of the ethanol aqueous solution in step A1 is 40-60 wt%.

[0015] In some embodiments, the mass ratio of the compound described in step A2 to 4,4'-difluorodiphenyl sulfone is (1.5-2):1.

[0016] In some embodiments, the mass ratio of bisphenol AF and 4,4'-difluorodiphenyl sulfone in step A3 is (1-1.3):1.

[0017] This application demonstrates that by specifying the mass ratio of the compound and 4,4'-difluorodiphenyl sulfone, as well as bisphenol AF and 4,4'-difluorodiphenyl sulfone, the yield of glufosinate can be further improved. This is likely because at this ratio, polyarylether sulfone has suitable porosity and microphase structure, which is beneficial for improving ion exchange efficiency. Furthermore, the appropriate number of rigid structures can ensure the mechanical strength of the ion exchange membrane, preventing cracks caused by membrane rupture during use that could affect the purity of glufosinate.

[0018] In some embodiments, the mass ratio of polyarylether sulfone and chloromethyl ethyl ether in step A4 is 1:(3.5-5).

[0019] In some embodiments, the mass ratio of chloromethylated polyarylene sulfone and tetramethylpropylene diamine in step A5 is 1:(0.04-0.07).

[0020] This application can increase the yield of glufosinate-ammonium salt by limiting the mass ratio of polyarylether sulfone and chloromethyl ethyl ether, as well as the mass ratio of chloromethylated polyarylether sulfone and tetramethylpropylenediamine. This may be because the system has a suitable cross-linking structure at this ratio, which can improve the acid and alkali resistance of the ion exchange membrane, thereby improving the stability of the membrane and increasing the yield of glufosinate-ammonium salt.

[0021] In some embodiments, the yield of glufosinate prepared is over 98%.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention first nanofiltrations the mother liquor of glufosinate to obtain a sodium-removed glufosinate solution, then introduces it into an electrodialysis system containing both a cation exchange membrane and a polyarylene ether sulfone anion exchange membrane for electrodialysis to obtain an ammonium chloride solution and a glufosinate solution. Finally, the solution is concentrated by evaporation to obtain inorganic salt products and glufosinate products. The aromatic ring structure and sulfone group of the polyarylene ether sulfone skeleton endow the ion exchange membrane with excellent mechanical properties and heat resistance, enabling it to operate stably for a long time under high temperature conditions. Furthermore, the aromatic ether structure can resist free radical attack, extending the service life of the ion exchange membrane.

[0023] (2) The present invention synthesizes polyarylether sulfone containing a block structure by setting the order of addition of monomer raw materials. Compared with random copolymers, the block structure ion exchange membrane containing a block structure has a higher ion permeability, which is beneficial to improving the yield of glufosinate.

[0024] (3) This invention introduces carvedilol segments onto the polyarylene ether sulfone (PAS) chain, thereby enabling the PAS anion exchange membrane to achieve a higher ion exchange rate. The carbazole group can inhibit the free rotation of the PAS backbone, allowing the polymer to form a looser stacking structure, thus creating more nanoscale pores within the membrane and promoting ion conduction. Furthermore, the increased incompatibility between the carbazole group and the flexible PAS chain promotes the microphase separation of the quaternary ammonium group and the hydrophobic backbone, forming continuous ion channels. In addition, the quaternary ammonium groups near the carbazole group unit are forced to extend due to steric hindrance, exposing more active sites and increasing the effective ion exchange capacity. Detailed Implementation

[0025] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0026] In the following examples and comparative examples, except for the polyarylether sulfone anion exchange membrane, all other related reagents and materials used were commercially available, and the cation exchange membrane was a DuPont Nafion 117.

[0027] Preparation Example 1 The preparation method of polyarylene ether sulfone anion exchange membrane-1 includes the following steps: A1. Add 5g carvedilol to 100ml of 50wt% ethanol aqueous solution, stir at 65℃ for 15min, adjust pH to 2, stir for 2h, and dry to obtain the compound; A2. Add 5g of the compound obtained in step A1 and 3g of 4,4'-difluorodiphenyl sulfone to 50ml of N-methylpyrrolidone, stir at room temperature for 15min, add 2.5g of potassium carbonate and 50ml of dimethyl sulfoxide, heat to 135℃ and react for 4h, then heat to 170℃ and react for 4h, then cool to 80℃ to obtain the reaction solution. A3. Add 1.7g bisphenol AF, 1.5g 4,4'-difluorodiphenyl sulfone, 1.25g potassium carbonate, 25ml dimethyl sulfoxide and 25ml N-methylpyrrolidone to the reaction solution obtained in step A2, heat to 140℃ and react for 4h, then heat to 170℃ and react for 4h to obtain the product. Add the product to deionized water to obtain the precipitate, wash and dry to obtain polyarylene ether sulfone. A4. Add 5g of the polyarylether sulfone obtained in step A3 to 50g of tetrachloromethane, stir to dissolve, cool to 0℃, add 21.25g of chloromethyl ethyl ether and 0.1g of tin tetrachloride, heat to 35℃ and react for 3 days to obtain the reactant. Add the reactant to anhydrous ethanol to obtain the precipitate, wash and dry to obtain chloromethylated polyarylether sulfone. A5. Add 5g of chloromethylated polyarylether sulfone obtained in step A4 to 50g of tetrachloroethane and stir for 25min. Add 0.275g of tetramethylpropanediamine and stir for 25s. Then cast it onto a flat glass surface, dry and peel it to obtain a film material with a thickness of 150μm. A6. The membrane material obtained in step A5 was successively immersed in 33wt% trimethylamine aqueous solution, 1mol / L sodium hydroxide aqueous solution and deionized water solution for 24h each, and then dried to obtain polyarylether sulfone anion exchange membrane-1.

[0028] Preparation Example 2 The preparation method of polyarylene ether sulfone anion exchange membrane-2 is the same as that in preparation example 1, except that the amount of compound added is 7.5g.

[0029] Preparation Example 3 The preparation method of polyarylene ether sulfone anion exchange membrane-3 is the same as that in preparation example 1, except that the amount of bisphenol AF added is 2.25g.

[0030] Preparation Example 4 The preparation method of polyarylene ether sulfone anion exchange membrane-4 is the same as that in preparation example 1, except that the amount of chloromethyl ethyl ether added is 27.5g.

[0031] Preparation Example 5 The preparation method of polyarylene ether sulfone anion exchange membrane-5 is the same as that in preparation example 1, except that the amount of tetramethylpropanediamine added is 0.45g.

[0032] Preparation Example 6 The preparation method of polyarylene ether sulfone anion exchange membrane-6 includes the following steps: A1. Add 5g of bisphenol AF and 3g of 4,4'-difluorodiphenyl sulfone to 50ml of N-methylpyrrolidone, stir at room temperature for 15min, add 2.5g of potassium carbonate and 50ml of dimethyl sulfoxide, heat to 135℃ and react for 4h, then heat to 170℃ and react for 4h, then cool to 80℃ to obtain the reaction solution. A2. Add 1.7g bisphenol AF, 1.5g 4,4'-difluorodiphenyl sulfone, 1.25g potassium carbonate, 25ml dimethyl sulfoxide and 25ml N-methylpyrrolidone to the reaction solution obtained in step A1. Heat to 140℃ and react for 4h, then heat to 170℃ and react for 4h to obtain the product. Add the product to deionized water to obtain the precipitate, wash and dry to obtain polyarylene ether sulfone. A3. Add 5g of polyarylether sulfone obtained in step A2 to 50g of tetrachloromethane, stir to dissolve, cool to 0℃, add 21.25g of chloromethyl ethyl ether and 0.1g of tin tetrachloride, heat to 35℃ and react for 3 days to obtain the reactant. Add the reactant to anhydrous ethanol to obtain the precipitate, wash and dry to obtain chloromethylated polyarylether sulfone. A4. Add 5g of chloromethylated polyarylether sulfone obtained in step A3 to 50g of tetrachloroethane and stir for 25min. Add 0.275g of tetramethylpropanediamine and stir for 25s. Then cast it onto a flat glass surface, dry and peel it to obtain a film material with a thickness of 150μm. A5. The membrane material obtained in step A4 is immersed in 33wt% trimethylamine aqueous solution, 1mol / L sodium hydroxide aqueous solution and deionized water solution for 24h each, and then dried to obtain polyarylether sulfone anion exchange membrane-6.

[0033] Example 1 A method for purifying and refining glufosinate-ammonium salt includes the following steps: S1. The mother liquor of glufosinate-ammonium salt is filtered and decolorized through a nanofiltration membrane to obtain a sodium-free glufosinate-ammonium salt solution. S2. The sodium-removed glufosinate solution obtained in step S1 is introduced into the desalination chamber of the electrodialysis system for desalination and concentration. Pure water is added to the concentrate chamber as the receiving liquid. The operating pressure of the electrodialysis system is 6 MPa, and the pH of the desalination chamber is 2, resulting in ammonium chloride solution and glufosinate solution. S3. The ammonium chloride solution obtained in step S2 is evaporated and concentrated to obtain an inorganic salt product; S4. The glufosinate solution obtained in step S2 is evaporated and concentrated to obtain glufosinate product. The nanofiltration membrane has a molecular weight cutoff of 300 Da; The electrodialysis system includes a Nafion 117 cation exchange membrane and a polyarylether sulfone anion exchange membrane-1.

[0034] Example 2 S1. The mother liquor of glufosinate-ammonium salt is filtered and decolorized through a nanofiltration membrane to obtain a sodium-free glufosinate-ammonium salt solution. S2. The sodium-removed glufosinate solution obtained in step S1 is introduced into the desalination chamber of the electrodialysis system for desalination and concentration. Pure water is added to the concentrate chamber as the receiving liquid. The operating pressure of the electrodialysis system is 4 MPa, and the pH of the desalination chamber is 2, resulting in ammonium chloride solution and glufosinate solution. S3. The ammonium chloride solution obtained in step S2 is evaporated and concentrated to obtain an inorganic salt product; S4. The glufosinate solution obtained in step S2 is evaporated and concentrated to obtain glufosinate product. The nanofiltration membrane has a molecular weight cutoff of 200 Da; The electrodialysis system includes a Nafion 117 cation exchange membrane and a polyarylether sulfone anion exchange membrane-1.

[0035] Example 3 S1. The mother liquor of glufosinate-ammonium salt is filtered and decolorized through a nanofiltration membrane to obtain a sodium-free glufosinate-ammonium salt solution. S2. The sodium-removed glufosinate solution obtained in step S1 is introduced into the desalination chamber of the electrodialysis system for desalination and concentration. Pure water is added to the concentrate chamber as the receiving liquid. The operating pressure of the electrodialysis system is 8 MPa, and the pH of the desalination chamber is 3, resulting in ammonium chloride solution and glufosinate solution. S3. The ammonium chloride solution obtained in step S2 is evaporated and concentrated to obtain an inorganic salt product; S4. The glufosinate solution obtained in step S2 is evaporated and concentrated to obtain glufosinate product. The nanofiltration membrane has a molecular weight cutoff of 500 Da; The electrodialysis system includes a Nafion 117 cation exchange membrane and a polyarylether sulfone anion exchange membrane-1.

[0036] Example 4 A method for purifying and refining glufosinate-phosphonium salt, the specific implementation method is the same as in Example 1, except that the polyarylether sulfone anion exchange membrane-1 is replaced with polyarylether sulfone anion exchange membrane-2.

[0037] Example 5 A method for purifying and refining glufosinate-phosphonium salt, the specific implementation method is the same as in Example 1, except that the polyarylether sulfone anion exchange membrane-1 is replaced with polyarylether sulfone anion exchange membrane-3.

[0038] Example 6 A method for purifying and refining glufosinate-phosphonium salt is described, with the specific implementation method being the same as in Example 1, except that the polyarylether sulfone anion exchange membrane-1 is replaced with a polyarylether sulfone anion exchange membrane-4.

[0039] Example 7 A method for purifying and refining glufosinate-phosphonium salt is described, with the specific implementation method being the same as in Example 1, except that the polyarylether sulfone anion exchange membrane-1 is replaced with a polyarylether sulfone anion exchange membrane-5.

[0040] Example 8 A method for purifying and refining glufosinate-phosphonium salt is described, with the specific implementation method being the same as in Example 1, except that the polyarylether sulfone anion exchange membrane-1 is replaced with a polyarylether sulfone anion exchange membrane-6.

[0041] Performance testing The yield of glufosinate in each example was calculated according to the formula: (mass of purified glufosinate / initial mass of glufosinate in the raw material) × 100%. The purity of glufosinate in each example was tested using gas chromatography. The test results are shown in Table 1. Table 1 As shown in Table 1, the phosphate-ammonium salt purification and refining methods in Examples 1-3 of this invention yield phosphate-ammonium salt with high yield and purity. A comparison of Examples 4, 5, and 1 shows that changing the ratio of the compound to 4,4'-difluorodiphenyl sulfone or bisphenol AF and 4,4'-difluorodiphenyl sulfone affects the porosity and microphase structure of the polyarylene ether sulfone anion exchange membrane, thus decreasing the yield and purity of the obtained phosphate-ammonium salt. A comparison of Examples 6, 7, and 1 shows that changing the ratio of polyarylene ether sulfone to chloromethyl ethyl ether or chloromethylated polyarylene ether sulfone to tetramethylpropylenediamine increases the cross-linking structure, making the polyarylene ether sulfone anion exchange membrane more prone to rupture and reducing its acid and alkali resistance, thus decreasing the yield and purity of phosphate-ammonium salt. A comparison of Examples 8 and 1 shows that the purity and yield of phosphate-ammonium salt are low when using an unmodified polyarylene ether sulfone anion exchange membrane directly.

[0042] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for purifying and refining glufosinate-phosphonium salt, characterized in that, Includes the following steps: S1. The mother liquor of glufosinate-ammonium salt is filtered and decolorized through a nanofiltration membrane to obtain a sodium-free glufosinate-ammonium salt solution. S2. The sodium-removed glufosinate solution obtained in step S1 is introduced into the desalination chamber of the electrodialysis system for desalination and concentration. Pure water is added to the concentrate chamber as the receiving liquid to obtain ammonium chloride solution and glufosinate solution. S3. The ammonium chloride solution obtained in step S2 is evaporated and concentrated to obtain an inorganic salt product; S4. The glufosinate solution obtained in step S2 is evaporated and concentrated to obtain glufosinate product. The electrodialysis system includes a cation exchange membrane and an anion exchange membrane; the anion exchange membrane is a polyarylether sulfone anion exchange membrane.

2. The method for purifying and refining glufosinate-phosphonium salt according to claim 1, characterized in that, The nanofiltration membrane has a molecular weight cutoff range of 200-500 Da.

3. The method for purifying and refining glufosinate-phosphonium salt according to claim 1, characterized in that, The operating pressure of the electrodialysis system is 4-8 MPa; the pH of the freshwater chamber is 2-3.

4. The method for purifying and refining glufosinate-phosphonium salt according to claim 1, characterized in that, The preparation method of the polyarylene ether sulfone anion exchange membrane includes the following steps: A1. Add carvedilol to an aqueous ethanol solution, stir at 60-70℃ for 10-20 min, adjust the pH to 1-3, stir for 1-3 h, and dry to obtain the compound; A2. Add the compound obtained in step A1 and 4,4'-difluorodiphenyl sulfone to N-methylpyrrolidone, stir at room temperature for 10-20 min, add potassium carbonate and dimethyl sulfoxide, heat to 120-150℃ and react for 3-5 h, then heat to 160-180℃ and react for 3-5 h, cool to 70-90℃ to obtain the reaction solution; A3. Add bisphenol AF, 4,4'-difluorodiphenyl sulfone, potassium carbonate, dimethyl sulfoxide and N-methylpyrrolidone to the reaction solution obtained in step A2, heat to 130-150℃ and react for 3-5 hours, then heat to 160-180℃ and react for 3-5 hours to obtain the product. Add the product to deionized water to obtain the precipitate, wash and dry to obtain polyarylene ether sulfone. A4. Add the polyarylene sulfone obtained in step A3 to tetrachloromethane, stir to dissolve, cool to 0°C, add chloromethyl ethyl ether and tin tetrachloride, heat to 25-45°C and react for 2-3 days to obtain the reactant. Add the reactant to ethanol to obtain the precipitate, wash and dry to obtain chloromethylated polyarylene sulfone. A5. Add the chloromethylated polyarylene sulfone obtained in step A4 to tetrachloroethane and stir for 20-30 minutes. Then add tetramethylpropylenediamine and stir for 20-30 seconds. Finally, cast the mixture onto a flat glass surface, dry it, and peel it off to obtain the membrane material. A6. The membrane material obtained in step A5 is immersed in trimethylamine aqueous solution, sodium hydroxide aqueous solution and deionized aqueous solution for 24 hours each, and then dried to obtain polyarylether sulfone anion exchange membrane.

5. The method for purifying and refining glufosinate-phosphonium salt according to claim 4, characterized in that, The concentration of the ethanol aqueous solution in step A1 is 40-60 wt%.

6. The method for purifying and refining glufosinate-phosphonium salt according to claim 4, characterized in that, The mass ratio of the compound described in step A2 to 4,4'-difluorodiphenyl sulfone is (1.5-2):

1.

7. The method for purifying and refining glufosinate-phosphonium salt according to claim 4, characterized in that, The mass ratio of bisphenol AF and 4,4'-difluorodiphenyl sulfone in step A3 is (1-1.3):

1.

8. The method for purifying and refining glufosinate-phosphonium salt according to claim 4, characterized in that, The mass ratio of polyarylether sulfone and chloromethyl ethyl ether in step A4 is 1:(3.5-5).

9. The method for purifying and refining glufosinate-phosphonium salt according to claim 4, characterized in that, The mass ratio of chloromethylated polyarylene sulfone and tetramethylpropylene diamine in step A5 is 1:(0.04-0.07).

10. The method for purifying and refining glufosinate-phosphonium salt according to any one of claims 1-9, characterized in that, The yield of the prepared glufosinate was over 98%.

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